19
TRANSFORMER BALANCED OUTs
As an option each output may be equipped
with high quality output transformers. These
transformers are controlled by a special
circuitry to achieve low inner resistance, very
good frequency range and low distortions.
They exceed IRT recommendations.
GP-I/O
This optional circuitry serves to externally
actuate the mute function of F355 or to control
external processes like “Rec-Light” by
internally or externally released mutes.
RELAIS
The relais is controlled by the internal /Mute
signal. During normal operation it is active,
under mute conditions it is released !!
Pin 1 of the Sub-D 9 connector is wired to the
NO (normally open) contact of the relais.
Pin 2 of the Sub-D 9 connector is wired to the
NC (normally closed) contact of the relais.
Pin 6 of the Sub-D 9 connector is wired to the
Common contact of the relais.
CURRENT SOURCE
Pin 7 of the Sub-D 9 connector is wired to an
internal current source. It delivers approx. 50
mA with a voltage of 24 V +/- 10%.
The current source is protected against
overload by means of a PTC.
CLASS-A FRONT END
As an option, each channel of MIC-AMP F355
may be equipped with a class-A input amplifier.
This option should only be installed ex works
or by trained professionals.
GROUND
Via Pin 3 the internal ground is accessible.
(PROTECTIVE EARTH)
The case of the Sub-D connector is screwed to
the case of F355 and therefore connected to
protective earth.
With the aid of two optocouplers an internal
mute may be released by external signals.
OPTOCOUPLER 1
This optocoupler is supplied internally.
If Pin 8 from the Sub-D 9 connector is wired to
ground this will release a mute.
OPTOCOUPLER 2
This optocoupler may be controlled via Pin 4
and Pin 9 of the Sub-D 9 connector totally
floating.
A mute is released when an external voltage is
connected to Pin 4 (+) and Pin 9 (-).
The built-in resistor is optimized for 12 V
external.
THE OPTIONS
